1. Field of the invention
The present invention relates to filling valves for use in counter-pressure filling machines and, in particular, to an improved tipless counter-pressure filling valve housing and process for weldless manufacturing of the same from one-piece stainless steel stock.
2. Description of the Background
Counter-pressure filling valves are typically used for filling of containers, such as cans or bottles, with carbonated liquids. Such valves ensure that the carbonated liquid which fills the can/bottle under pressure does not leak from the machine during filling or that the carbonation does not escape from the liquid as the container is filled.
Traditional methods and devices for filling containers with carbonated liquids include a variety of counter-pressure filling machines in which the cans/bottles are first filled with a gas under pressure. Carbonated liquid is then admitted to the cans/bottles under pressure so that the carbonated liquid cannot escape. The cans/bottles are then sealed to ensure that the carbonation does not escape the liquid.
One example of a filling valve for a carbonated liquid bottling machine is shown in U.S. Pat. No. 4,089,353 to Antonelli. The Antonelli '353 filling valve is controlled by a cam outside of the tank. The cam actuates a first valve member to admit counter-pressure gas into the can. The can is filled with the counter-pressure gas until the pressures of the gas and the liquid are equal. The cam then opens a second valve member which allows the liquid to flow into the container. When the container is filled, the cam actuator closes the valve members and the bottle is lowered away from the valve.
Another type of filling valve is illustrated by U.S. Pat. No. 4,679,603 to Rademacher et al. The Rademacher et al. '603 filling valve incorporates two concentric valve members. The outer valve member admits liquid into the container, and the inner valve member admits counter-pressure gas into the container. The outlet dispensing end or "vent tube" for the inner valve member must be inserted a certain distance into the container for proper operation of the filling valve.
Still another variation is shown in U.S. Pat. No. 5,156,200 to Mette, which discloses a counterpressure filling valve comprising a downwardly extendable sleeve which can descend toward an empty container below the valve, and which carries a deformable annular sealing element 2 which is movable into sealing engagement with the container to be filled.
The above and other commercially available counter-pressure filling devices employ valve housings that provide a high volume fluid interface between the filling equipment and cans or bottles to be filled. Each piece of filling equipment may employ a large number of valve housings to simultaneously fill an equal number of cans or bottles.
For instance, FIG. 1 is a perspective photo and FIG. 2 is a side-cross section of an existing counter-pressure filling valve housing of the type that is commercially available from Crown-Simplimatic Co. This valve and refinements thereto are described in detail in a family of patents, including U.S. Pat. Nos. 5,150,740; 5,145,008; 5,139,058; 4,986,318; 4,750,533; 4,442,873, all issued to Yun and all drawn to counterpressure filling valves for introducing counterpressure gas and product into a container. The valves are actuated through the physical engagement of the container to be filled; thus, the filling operation is achieved without the use of external valve operating cams or the like.
As shown in FIGS. 1 and 2, the prior art valve body 10 generally includes a cylindrical mid-section 16, a port block section 11, and a valve cap section 13. A flange 12 atop mid-section 16 bears apertures 14 by which the fill valve body 10 is mounted to beverage machinery in a conventional fashion. A plurality of discharge nozzles 28 extend downward from valve cap section 13 and these typically define as few as nine and as many as fifteen discharge ports. The mid-section 16 is hollow such that beverage, such as a carbonated drink, selectively flows through. The hollow cylindrical mid-section 16 merges into an integral radially extending bottom flange 18 that leads into a downwardly directed annular collar 22. Collar 22 is angularly drilled and tapped at the nine to fifteen separate sites to define a plurality of axial channels through which the beverage flows out of the hollow mid-section 16. The lower surface 24 of the collar 22 accommodates interference fit insertion of a corresponding number of beverage discharge nozzle tips 26. Each nozzle tip 26 is in communication with one of the internal beverage passageways disposed in flange 18 and collar 22. Each tip 28 of the array is, thus, diagonally disposed in a downward and outward direction and internally comprises a single, angularly oriented, linearly extending central bore. The tips 28 collectively fit through the top opening at the upper lip or edge of a beverage can. The sizing and orientation of the array 26 of nozzle tips 28 discharges and directs beverage into the can in a plurality of circular streams against the interior surface of the side of the can near the top thereof. This minimizes foaming of the beverage.
The valve body 10 also comprises a central wall 30 with aperture 33 for introduction into the can of pressurized gas. Valve body 10 also comprises a separate, exteriorly disposed helical tube 34, the hollow of which functions to snift gas from the top of the before removing the can from the filling equipment. Tube 34 leads into a hollow through flange 18 and collar 22 and to a is port located adjacent the slot 36. In accordance with conventional operation, pressurized gas at the top of the can is evacuated or "snifted" just before the can is removed from the filling machinery.
Unfortunately, the above-described valve housing has a number of drawbacks. First, the filling valve tips 20 are formed from sections of stainless steel pipe that are compression-fit into the collar 22. This greatly complicates the manufacturing process as bore-holes must be drilled into the collar 22 and then each valve tip 28 must be press-fit by hand. The resulting valve housing is overly complex and expensive.
Moreover, the filling valve must have a relatively long stroke to meet the containers while ensuring that the valve tips 20 are inserted the proper depth in the container and that they are lifted clear from the container after the container is filled with the carbonated liquid. The requirement of moving the filling valves along this relatively long stroke significantly slows down the overall operation of stationary container filling machines.
The conventional process for manufacturing the above-described valve bodies also has shortcomings. The hollow cylindrical mid-section 16, valve cap 13, and port block 11 are separately machined from three individual pieces of stainless steel stock. These three components are then welded together to form the illustrated valve housing. Further machining takes place, e.g., to bore holes for valve tips 28, and the valve tips 28 are then press-fit by hand into the valve collar 22. This complex process was previously thought to be necessary due to the various intersecting channels in and through the valve body 10, plus the irregular protruding port block 11. However, the process is costly and greatly adds to the time it takes for the filling is valve housing to be manufactured. Even worse, the process results in several weld-lines 19. These weld-lines 19 are highly susceptible to the accumulation of liquid and increase the risk of contamination and disease.
U.S. Pat. No. 5,141,135 to Nish et al. shows a partial solution in the form of an adapter nozzle to eliminate the tips 28, and said adapter is shown in FIG. 3 herein. A portion of the valve body including the tips 28 must be removed, and then the adapter nozzle is fastened to the non-removed portion. The adapter discharges fluid in three broad thin streams angularly against the interior walls of the can. While the tips are eliminated, the adapter approach raises problems of its own. The tips must be machined off smoothly and the adapter attached securely to ensure proper operation. Even so, the adapter is yet another welded part that further compromises structural integrity.
It would be greatly advantageous to develop a simpler and more cost effective valve housing and manufacturing process therefor which eliminates both welding and valve tips.